Home theater brings with it what we call an
"Approach-Avoidance" conflict. We all want high power
for those thunderous sound tracks, but the closer we get to
writing that four-digit check for power amplifiers that deliver
three-digit wattage per channel (and the first digit is not a 1),
the more we say, "Can I really afford this?"

Several companies make high end products
that are marketed directly to consumers through mail order. They
represent good value, when they are good performers, but the
problem is that, since the manufacturer sells direct, you can't
audition the product in a dealer showroom. Instead, potential
buyers must rely on reviews in magazines that care about giving
these small companies some space and also care about letting
readers know about products that give a major bang for the buck.
Secrets of Home Theater and High Fidelity is such a magazine, and
the Cinepro 600x is such a product.

Although readers might not be familiar with
the name Cinepro, apparently we have been listening to the
industrial version for about 5 years. This amplifier was
originally made for use in movie theaters (the ones where you pay
$4.00 for popcorn, not the home movie theater variety). It is THX
certified (the industrial version), and about 5000 of them are in
use. Cinepro took the industrial model, beefed up the power
supply, reduced the noise level, and upgraded various parts
(capacitors and resistors). The newly designed brushed aluminum
black faceplate now says Cinepro Professional, but the top of the
chassis still has some yellow printing that warns the user, in
English and French, about being careful not to get shocked and to
guard against moisture (see photo). A rocker on/off switch is on
the front panel along with three pairs of LEDs (one pair for each
channel) that indicate power on, signal being fed to the
amplifier, and soft clipping (when this light flashes, it means
the amp is going into unacceptable distortion levels, and
circuitry suppresses the high level signals so that hard clipping
does not occur). The back of the amplifier has two 1/4"
phone plug unbalanced inputs, to which RCA jack-Phone solid metal
gold plated plug adapters (supplied) are inserted for standard
RCA plug interconnects (see photo), two XLR balanced input jacks,
a ground lift switch (for ground loop hum reduction), a bridged
(mono)/stereo switch, and two pairs of plastic speaker cable
binding posts. For bridged operation, you switch to bridged mode
and use the red speaker binding posts (one from each of the two
amplifier channels). The Cinepro is labeled as a "Six
Hundred Watt Theater Amplifier". It is 600 watts rms: 300
watts rms/ch into 4 Ohms, which is the standard for movie theater
operation. For home use, however, we feel it should be called a
"Four Hundred Watt Home Theater Amplifier" since 8 Ohm
speakers are more the norm in homes, and this is, after all, a
home theater amp (and get rid of the yellow printing on the top,
please).

In listening to the Cinepro, we found that
it has an extremely clean, crisp mid-range. However, it is not
overdone (not harsh or gritty). The highs and lows seem to be
neutral. Perhaps the mid-range crispness is due to the original
use of the amp in theaters where it would be difficult to
understand dialog if the mid-range were soft. But, as I said, it
is not overdone, and in fact, this sonic characteristic was
preferred to a set of pure class A power amps by two of our three
referees. Only 20 dB of negative feedback are employed,
undoubtedly one reason the mid-range is not too sibilant. The
output devices are bipolar (Motorola TO-3, six per channel),
which can produce a crisp tonality in amplifiers, compared to the
warmer sound of MOSFETs. Three gain stages are used before the
final output stage. There is current protection circuitry and a
servo-driven cooling fan present in spite of a bias setting of
only about 5% into class A, and we found that even when the amp
was driven hard, it did not get very warm at all. The protection
and cooling fan are probably to protect it in the 12 hours/day -
speakers in parallel abuse that it could get in commercial
theaters. We were pleased to see the balanced XLR jacks since
many amps these days have long interconnect runs to contend with.
The bridged mono capability and ground lift are also handy (the
Cinepro had a bit more noise and hum than other - much more
expensive - amps). We would prefer that the unbalanced jacks were
RCA to begin with, instead of having to use adapters for
conversion of the phone plugs to RCA plug use, since, let's face
it, any additional physical interface connections will detract
from signal purity, even if it is ever so little. However,
modifications of the basic original design cost money, and Eric
Abraham (Cinepro's CEO) elected to keep the price as reasonable
as possible (the yellow lettering isn't really all that bad).

We measured 103 dB SPL output from two 88
dB/W/M sensitivity speakers using a CD with a musical power
spectrum of 63 Hz to 6 kHz (smaller amounts of signal on either
side of this spectrum) before the sound began to get mushy and
harsh. At 105 dB, the soft clipping lights came on, suggesting
that the full usable output was being delivered at 103 dB. This
is more than enough volume for any listener (really, we should be
keeping the average volume much lower to protect our ears from
damage). With a meatier power supply (the Cinepro has a hefty EI
core transformer, but only 20,000 mfd capacitance), probably more
usable power could be extracted from this amp, but again, at
higher cost.

For $699, the Cinepro 600x is an excellent
buy. It is well built, has plenty of features, and best of all,
solid sound. With three of these, you could have (into 8 Ohm
speakers) 200 watts to each of four channels (front left/right
and rear left/right) and 600 watts (bridged mono) to the center
channel, all for a hair more than two kilobucks. It has a 30 day
no questions asked money back guarantee, and three years parts
and labor warranty. If you are planning for AC-3, where full
frequency spectrum sounds are being delivered to all channels, or
you just want a high powered Pro Logic amp setup, this could be
the ticket to ride at very reasonable cost.